Glossary
Activities of daily living (ADLs)—Activities related to personal care, including bathing, dressing, getting in or out of bed or chair, using the toilet, and eating.
Ambulatory care—Health services that are provided on an outpatient basis, in contrast to services provided in the home or to persons who are inpatients. Although many inpatients may be ambulatory, the term “ambulatory care” usually implies that the patient must travel to a location to receive services that do not require an overnight stay.
Bundled payment—Strategy for reducing health-care costs that involves reimbursement for multiple providers bundled into a single, comprehensive payment that covers all of the services involved in the patient’s care.
Case-control study—A type of observational study where patients with a certain outcome or disease and an appropriate group of controls without the outcome or disease are selected and then information is obtained on whether the subjects have been exposed to the factor under investigation.
Clinic—An administrative unit of a hospital outpatient department where ambulatory medical care is provided under the supervision of a physician.
Cohort study—A type of observational study where data are obtained from groups who have been exposed, or not exposed, to the factor of interest. No allocation of exposure is made by the researcher.
Comorbidities—Conditions that exist at the same time as the primary condition in the same patient.
Cross-sectional study—A type of observational study that examines the relationship between diseases (or other health-related characteristics) and other variables of interest as they exist in a defined population at one particular time.
Disability—The law defines disability as the “inability to engage in any substantial gainful activity (SGA) by reason of any medically determinable physical or mental impairment(s) which can be expected to result in death or which has lasted or can be expected to last for a continuous period of not less than 12 months” (CFR § 404.1505). The American Medical Association (AMA) defines disability as “activity limitations and/or participation restrictions in an individual with a health condition, disorder, or disease.”
Emergency department (ED)—An emergency department, also known as an accident and emergency department (A&E), emergency room (ER), emergency ward (EW), or casualty department, is a medical treatment facility specializing in emergency medicine and the acute care of patients who present without prior appointment, either by their own means or by that of an ambulance. The emergency department is usually found in a hospital or other primary care center.
Emergency Medical Treatment and Labor Act (EMTALA)—An act of the US Congress passed in 1986 that ensures public access to emergency services regardless of ability to pay.
Gainful activity—Work activity usually done for pay or profit, whether or not a profit is realized. SSA considers the impairments in the Listing of Impairments to be severe enough to prevent a person from doing any gainful activity, regardless of age, education, or work experience.
Health-care utilization—The use of health-care services for a variety of reasons, including to prevent or cure disease, to reduce pain, to improve quality of life, or simply to obtain more information about health status.
Home health care—Home health care as defined by the National Home and Hospice Care Survey is care provided to individuals and families in their place of residence for promoting, maintaining, or restoring health; or for minimizing the effects of disability and illness, including terminal illness.
Hospital—According to the American Hospital Association, a licensed institution with at least six beds whose primary function is to provide diagnostic and therapeutic patient services for medical conditions by an organized physician staff and has continuous nursing services under the supervision of registered nurses.
Impairment—According to SSA, “an impairment or combination of impairments that significantly limit the individual’s physical or mental abilities and, as a result, interfere with the individual’s ability to perform basic work activities.” The AMA defines impairment as “a significant deviation, loss, or loss of use of any body structure or body function in an individual with a health condition, disorder, or disease.”
Instrumental activities of daily living—Activities related to independent living, including preparing meals, managing money, shopping for groceries or personal items, performing light or heavy housework, and using a telephone.
Length of stay—The duration of a single episode of hospitalization, calculated by subtracting the day of admission from the day of discharge.
Listing of Impairments (Listings)—The SSA Listing of Impairments describes, for each major body system, impairments considered severe enough to prevent an individual from doing any gainful activity. The criteria in the Listing of Impairments are applicable to evaluation of claims for disability benefits under the Social Security Disability Insurance program or payments under
the SSI program. The criteria in the Listing of Impairments apply only to one step of the multistep sequential evaluation process. At that step, the presence of an impairment that meets the criteria in the Listing of Impairments (or that is of equal severity) is usually sufficient to establish that an individual who is not working is disabled. However, the absence of a listing-level impairment does not mean the individual is not disabled. Rather, it merely requires the adjudicator to move on to the next step of the process and apply other rules in order to resolve the issue of disability.
Long-term care—Services and supports necessary to meet health or personal care needs over an extended period of time.
Medicaid—Medicaid provides health coverage to millions of Americans, including eligible low-income adults, children, pregnant women, elderly adults, and people with disabilities. Medicaid is administered by states, according to federal requirements. The program is funded jointly by states and the federal government.
Medical home—Also known as the patient-centered medical home (PCMH). A team-based health-care delivery model led by a health care provider that is intended to provide comprehensive and continuous medical care to patients with the goal of obtaining maximized health outcomes.
Medicare—Administered by the federal government since 1976, Medicare is a single-payer, national social insurance program, which currently uses about 30–50 private insurance companies across the United States. The US Medicare program is funded by a payroll tax, premiums and surtaxes from beneficiaries, and general revenue. It provides health insurance for Americans aged 65 and older who have worked and paid into the system through the payroll tax. It also provides health insurance to younger people with some disabilities status as determined by the Social Security Administration, as well as people with end-stage renal disease and amyotrophic lateral sclerosis.
Negative predictive value (NPV)—The proportion of negative results that are true negatives, i.e., number of true negatives/(number of true negatives + number of false negatives).
Nursing home—An establishment licensed as a nursing home with three or more beds that routinely provides nursing care services. Homes providing only personal or domiciliary care are excluded. Facilities included are either certified by Medicare or Medicaid, or they are not certified but licensed by the state as a nursing home. These facilities may be freestanding or distinct nursing care units of larger facilities.
Outpatient—A patient who is receiving ambulatory care at a hospital or other facility that also provides inpatient care without being admitted to the facility.
Patient Protection and Affordable Care Act (ACA)—A US federal statute designed to increase health insurance quality and affordability, lower the uninsured rate, and reduce costs of health care. Signed into law on March 23, 2010.
Positive predictive value (PPV)—The proportion of positive results that are true positives, i.e., number of true positives/(number of true positives + number of false positives).
Randomized controlled trial (RCT)—An experimental comparison study in which participants are allocated to treatment/intervention or control/placebo groups using a random mechanism.
Readmission—An episode when a patient who had been discharged from a hospital is admitted again within a specified time interval.
Receiver operating characteristic (ROC) curve—A plot of the true positive rate against the false positive rate for the possible cut points of a diagnostic test, to demonstrate tradeoff between sensitivity and specificity, and to examine the accuracy of the test.
Sensitivity—The proportion of positives that are correctly identified as such, i.e., true positives/(true positives + false negatives).
Severe impairment—According to the Social Security Administration, “At step 2 of the sequential evaluation process, an impairment or combination of impairments is considered ‘severe’ if it significantly limits an individual's physical or mental abilities to do basic work activities.”
Skilled care—Nursing care such as help with medications and caring for wounds, and therapies such as occupational, speech, respiratory, and physical therapy. Skilled care usually requires the services of a licensed professional such as a nurse, doctor, or therapist.
Social Security Disability Insurance (SSDI)— The SSDI program provides disability benefits to people who are under the full retirement age and are no longer able to work because of a disabling medical condition or because they have a terminal illness.
Specificity—The proportion of negatives that are correctly identified as such, i.e., true negatives/(true negatives + false positives).
Substantial gainful activity (SGA)—Work activity, that involves doing significant physical or mental activities, usually done for pay or profit, whether or not a profit is realized. According to the Social Security Administration, “a person who is earning more than a certain monthly amount (net of impairment-related work expenses) is ordinarily considered to be engaging in SGA. The amount of monthly earnings considered as SGA depends on the nature of a person’s disability. The Social Security Act specifies a higher SGA amount for statutorily blind individuals; Federal regulations specify a lower SGA amount for non-blind individuals. Both SGA amounts generally change with changes in the national average wage index.”
Supplemental Security Income (SSI)—The SSI program is a means-tested income-assistance program for disabled, blind, and aged people who have limited income and resources regardless of their prior participation in the labor force.
Systematic evidence review—Scientific investigation that focuses on a specific question and uses explicit, preplanned scientific methods to identify, select, assess, and summarize the findings of individual, relevant studies.
Technology-based health—The use of mobile technologies to provide individual-level interventions to consumers for health care, for example, text messaging interventions to increase medication adherence.
Telehealth—Technologies and tactics used to virtually deliver health-care and health education services, including telemedicine, which refers to traditional clinical diagnosis and monitoring administered through technological platforms.
